Method of and apparatus for feeding a substantially untwisted multifilament strand



Dec. 20, 1966 w. w. DRUMMOND METHOD OF AND APPARATUS FOR FEEDING A SUBSTANTIALLY UNTWISTED MULTIFILAMENT STRAND 4 Sheets-Sheet 1 Filed Nov. 29, 1963 INVENTOR. W. W. MUMMO/VD ATI'OKNEV Dec. 20, 1966 w. w. DRUMMOND METHOD .OF AND APPARATUS FOR FEEDING A SUBSTANTIALLY UNTWISTED MULTIFILAMENT STRAND 4 Sheets-Sheet 2 Filed Nov. 29, 1965 7 INVENTOR.

W W DRUMM 0N0 ATTOKNEV Dec. 20, 1966 w. w. DRUMMOND 3,293,013

METHOD OF AND APPARATUS FOR FEEDING A SUBSTANTIALLY UNTWISTED MULTIFILAMENT STRAND Filed Nov. 29, 1963 V 4 sheets sheet 5 4 I WWURUMMOl/D INVENTOR Dec. 20, 1966 w. w. DRUMMOND 3,293,013

METHOD OF AND APPARATUS FOR FEEDING A SUBSTANTIALLY UNTWISTED MULTIFILAMENT STRAND Filed Nov. 29, 1963 4 Sheets-Sheet 4 INVENTOR.

W. W. [7/9 UM M 0ND ATTORNEY United States Patent METHOD OF AND APPARATUS FOR FEEDING A SUBSTANTIALLY UNTWISTED MULTI- FILAMENT STRAND Warren W. Drummond, Allison Park, Pa., asslgnor to Pittsburgh Plate Glass Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Nov. .29, 1963, Ser. No. 326,697 9 Claims. (Cl. 65-2) This invention relates to the production of glass fibers and glass fiber products. More particularly the invention relates to a method and apparatus for feeding a substantially untwisted multifilament strand.

The method and apparatus of the present invention are especially suitable for the continuous attenuation of glass filaments from streams of molten glass flowing from orifices in a fiber glass bushing. This is accomplished by applying tractive forces to the streams of glass, so as to attenuate the streams, and to feed a group of the formed filaments in a substantially untwisted, multifilament strand.

In the past the streams of glass have been attenuated by the engagement of the filaments with the exterior of a sleeve received on a rotary spindle and the strand is wound on the sleeve as a forming package. In this method of attenuating and collecting the strand there is an increasing build-up of tension on the mass of the accumulating filaments as they are Wound upon the constantly increasing exterior of the sleeve. These filaments must be subsequently unwound from the package to further process the strand and because of the tension that has been builtup some difiiculty has been encountered in removing the strand from the package. As can be understood with the diameter of the package changing as the filaments are collected thereon, there is a change in the attenuating force which would, in the absence of other controls, cause a product variation because the attenuating force would vary. To compensate for the variation in attenuating forces elaborate temperature control means are generally provided, so as to change the viscosity of the glass in the stream. Temperature compensation is merely a compromise, so that there exists in the strand a variation in filament diameter.

It has been suggested that various forms of mating wheels be used to apply the attenuating force to the filaments. Such wheels have not been too satisfactory because of the tendency of the gathered fibers to separate and to lick around the periphery of the wheels. This problem is especially severe when the peripheral speeds of the wheel reaches a speed that makes the process commercially feasible. Speeds as high as 8,000 to 15,000 feet per minute are not uncommon in the process of producing multifilament strand.

Many attempts have been made to modify pulling Wheels, so as to project the fibers from the bite between the wheels in which the fibers are received. In one attempt to overcome the prior art difiiculties, the strand is deformed because of the peripheral contour of the mating wheels. In others, there have been modifications of the Wheel peripheries in order to utilize centrifugal force acting on the wheels to physically engage the fibers and to project them in a desired path of travel.

In accordance with the present invention the streams of molten glass flowing from a fiber glass bushing are gathered into a strand after a hinder or size is applied to the individual filaments and the strand is fed between a pair of engaging surfaces which move at a high rate of speed, on the order of 5,000 and generally more feet per minute. Engagement of the strands by the surfaces applies an attenuating force on the filament and also moves Patented Dec. 20, 1966 the strand in a given direction. The direction of movement of the engaging surfaces is .abruptly changed while the movement imparted to the strand is continued in the same direction. No licking of the filaments of the strand occurs because of the abrupt change in the path of movement of engaging surfaces and the force of inertia acting on the strand. The strand is not deformed in any manner and can be collected in a bucket, on a forming tube driven in the manner disclosed in copending application Serial No. 176,734, filed March 1, 1962, entitled Production of Fiber Glass Strand, or may be deposited on a toraminous conveyor as a mat. Because of the uniformity of attenuating force, the diameter of each fiber is uniform throughout its entire length.

The inventive concepts will "become more apparent from the consideration of the specification and the accompanying drawings in which:

FIG. 1 is a three-quarter view showing one form of apparatus of this invention together with the fiber forming bushing, a binder applicator and a gathering shoe;

FIG. 2 is an enlarged view showing one arrangement of the apparatus of this invention;

FIG. 3 is a side view of the apparatus shown in FIG. 2;

FIG. 4 is a view similar to FIG. 2 and showing another arrangement of the apparatus of this invention;

FIG. 5 is an elevational view of the apparatus of FIG. 4 adapted for laying the strand down onto a foraminous conveyor as a mat product;

FIG. 6 shows a different embodiment of the invention in Which a bearing pin is oscillated and the mechanism for oscillating or reciprocating the bearing pin; and

FIG. 7 shows a still different embodiment with means for oscillating or reciprocating at least one of the belts which engage the strand.

In the various figures the same reference characters will be used to refer to the same parts.

Turning now to FIG. 1, there is a fiber forming bushing 10 containing a mass of molten glass 12 which flows as streams through a plurality of bushing orifices or tips 14. There may be 200 to 400 or more tips in .a bushing. The streams are attenuated into filaments 16 by means of a strand pulling device generally identified as 1-8 and which will be later described in detail. The filaments 16 are directed so as to engage a belt 20 of a binder applicator device of conventional construction, generally identified as 22. The belt 20 is endless and is driven by a pulley 24 which in turn is driven by a suitable prime mover (not shown). The applicator 22 is supported by suitable support means 28, so that it is rigidly positioned at its desired location. A binder, such as starch, is controllably delivered to the belt 20 and by contact therewith to the filaments 16. Other types of binder and binder applicators can be used without departing from the spirit of the invention.

The binder coated filaments are then directed over a gathering shoe 30 and gathered thereby into a substantially untwisted multifilament strand 32. The strand 32 is directed between engaging portions of the belts 34 and 36 of the mechanism 18 and are discharged at the bottom of the mechanism 18 for collection by any wellknown means or on a foraminous conveyor.

The belt 34 of the device 18 is driven by the pulley 38 in turn driven by a suitable prime mover, identified as motor 40, supported by a mounting plate 41. The motor 40 may be an air motor of conventional design, supplied by air under pressure through the hose 42 which in turn is connected to a suitable source of such air under pressure. The pulley 38 is driven at a rapid rate such that the lineal speed of its periphery is on the order of 5,000 and generally more feet per minute. Pulleys of between 3 inches and 8 inches in diameter have been found to operate satisfactorily. The belt 34, generally made of a 3 synthetic fiber, such as nylon, or other known synthetics is extremely thin, on the order of 0.010 inch to 0.040 inch in thickness and Ms inch or more in width, is flexible and passes over a stationary bearing pin 44 fixedly attached to a mounting bracket 46. Adjustment of the position of the bearing pin 44 is accomplished by adjustment of the position of the mounting bracket 46. The

mounting plate 41 is provided with an arcuate slot 48 and receives bolts 50 which pass through slots 52 in the bracket 46. The bearing pin 44 is much less in diameter than the pulley 38, so that as the belt 34 passes around the bearing pin it abruptly changes its direction of travel. To accomplish the abrupt change in direction, pins of inch to /2 inch in diameter have been found to be satisfactory. The speed at which a rotating bearing pin would rotate precludes the rotation of the bearing pin because for such speeds no suitable bearings are known. For example, a pin of A inch in diameter would be required to rotate at approximately 80,000 r.p.m. when the linear speed of a strand reached 5,000 feet/minute. Higher linear strand speeds, which are now being attained, will result in a higher rotational speed.

The belt 36, which has a portion engaging the belt 34, is driven by a pulley 56 driven by a suitable prime mover (not shown) or by suitable drive mechanism from the motor 40, for example, a belt drive arrangement similar to that to be described with reference to FIG. 5. The belt 36 is generally identical to the belt 34 and passes over a stationary bearing pin 58 also generally identical to the pin 44. The belt 36 in passing around the bearing pin 58 abruptly changes its direction of travel. The strand 52 is engaged by the belts 34 and 36 along their engaging portions and is rapidly moved downwardly, so that an attenuating tractive force is applied to the streams of glass from the tips 14 to form the filament 16. The downward movement of the strand, because of the force of inertia, is continued as the strand is discharged from the engaging surfaces of the belts 34 and 36. The abrupt change in direction of the belts as they pass around their respective bearing pin insures the continuation of the direction of motion of the strand because of the force of inertia acting on the strand which precludes licking of the strand or the filaments around the belts and the respective bearing pins. In addition, the centrifugal force acting on the belts throws any binder adhering thereto, due to engagement with the strand, from the belts. The centrifugal force is approximately 50,000 Gs when the belt travels at 10,000 feet per minute over a /2 inch diameter pin.

The bearing pin 58 is mounted in the same manner as the bearing pin 44, in that its position may be adjusted by means of a slotted bracket 46 and bolts 50 passing through slots 52 in the bracket 46 and an arcuate slot 48 in the plate 41.

As stated, the bearing pins 44 and 58 are stationary members because it is not possible to provide suitable bearings rotatable at speeds on the order of 80,000 r.p.m., those encountered in the operation of the device. Lubrication of the pin and the belt is provided by supplying a cooling fluid, such as water, to the bearing surface. One means for providing such lubrication will be later described in detail.

Attention is now directed to FIGS. 2, 3 and 4 showing the device 18 in larger scale. FIGS. 2 and 4 differ in the positioning of the bearing pins 44 and 48. The mechanical structure of the device in the two figures is the same. Other arrangements of the various parts are possible by changing the positions of the pins 44 and 58. Nevertheless, the principle of operation is the same. FIG. 3 is a side view of the arrangement illustrated in FIG. 2 and shows constructional details. The pulley 38 is affixed to the shaft 60 of the air motor 40 by an acorn nut 62. The pulley 56 is supported on a shaft 64 rotatably supported in a journal 66 connected to the plate 48. The shaft 64, as before stated, may be driven by a suitable motor or may, by means of a drive mechanism,

be driven by the motor 40. It is important, however,

that the pulleys 38 and 56 be driven at the same speed.

As indicated previously, lubrication of the bearing surface between the belts 34 and 36 and the bearing pins.

44 and 58 is desirable. One mechanism for providing such lubrication is shown in FIG. 3. Each pin 44 and 58 is provided with a central bore 68 terminating in an opening at the end of the pin where the pin is connected to the plate 41. The bore 68 extends to within a short distance of the other terminal end of the pin. Each pin is counterbored as at 70, so as to communicate the bores 68 and 70 and with the exterior of the pin. A hose 72 connected to the pin 44 and to a source of water (not shown) supplies water to the bore 68, the counterbore 70, and to the bearing surface between the pin 44 and the belt 34 and eliminates the build-up of frictional heat.

Other fluids, such as air under pressure, could be used for the same purpose and in the absence of bores and j' counterbores in each pin, water may be sprayed or dripped onto the surface of the pins from above the pin. Attention is now directed to FIG. 5 showing the pulling device 18 mounted for reciprocal movement on a support.

which extends from side to side and above a foraminous conveyor 92. Means such as air motor plus suitable limit 1 switches may be provided for moving the device 18 1 throughout the limits of the support 90 and from side to side over the foraminous conveyor which, as illustrated in the drawing, moves in a direction normal to the move:

ment of the pulling device 18. The speed of the conveyor and the reciprocating speed of the device 18 determines,

the density of the product.

FIG. 5 also illustrates a suitable drive mechanism for driving the pulleys 36 and 56 at the same speed. Here i the pulley 36 is mounted on a shaft 96 having a second pulley 98 attached thereto but on the opposite side of the mounting plate from the pulley 36. The pulley 56 like wise is mounted on a shaft 100 having a second pulley 102 f An endless belt 104 is entrained over attached thereto. the pulleys 98 and 102, as shown, and also over a drive pulley of a suitable prime mover (not shown). Identical rotational speeds are thus insured. Also, the drive arrangement permits side to side movement of the plate 41 as a carriage without movement of the driving prime mover.

It is also possible to oscillate or reciprocate the pin 44 and/or the pin 58 to deposit the strand in large diameter convolutions. As shown in FIG. 6, oscillation of the pin 44 may be accomplished by connecting the pin 44 to a crank 106 which in turn is connected to an eccentric 108 i rotated by means of a mOt0r,s0 as to oscillate the pin at the desired frequency. The pin 44 must be so mounted 1 to move in a desired path. When the pin 44 is oscillated,

the path of movement of the strand being discharged is more pronounced than in the absence of such oscillation,

Oscillation of the pin 34 is desirable in the formation of a mat product in that a mat can be produced having a high degree of integrity without the use of a binder in the r mat.

Another form of apparatus for varying the path of, strand discharge is illustrated in FIG. 7. In this modification, a bladed rotor 110 is located between the flights of reciprocated. To reciprocate both bearing pins is within the scope of this invention.

In the foregoing, only a single strand has been described as being engaged by the belts. It is possible to perate With multiple strand and maintain them separate at least until discharge. Spacings of 4; inch therebetween will sufiice. If the strands are wound, then they may be separately wound or wound simultaneously on the same package.

What is claimed is:

1. A method of producing glass fibers from a source of molten glass flowing through a plurality of orifices which comprises,

gathering said fibers into a strand,

introducing said strand between at least two opposing flexible surfaces, each moving in the same direction at substantially the same high rate of speed,

said flexible surfaces being engaged with one another during the movement thereof for a distance sufiicient to impart a high velocity to said strand engaged with said flexible surfaces,

moving at least one of said opposing flexible surfaces away from the other of said surfaces to permit said strand to remain in contact with a moving flexible surface,

abruptly changing the direction of the movement of the flexible surface having the strand in contact therewith at a point on said flexible surface where said flexible surface and said strand are engaged until the direction of movement of said last named flexible surface is at a sharp angle to said direction of movement of said strand,

whereby said strand is projected into space at a high rate of speed.

2. In apparatus for producing fiber glass which includes a source of molten glass,

a fiber forming bushing having a plurality of orifices through which molten glass from said source flows streams and which streams are attenuated into fibers, and

means to gather said fibers into a strand,

the improvement which comprises,

a pair of endless belts having surface portions which engage one another and between which the strand is fed to be engaged by said engaging surface portions,

means to rapidly move said belts along a predetermined path so as to move said engaged strand along the same path and to apply attenuating forces to said fibers,

and a smooth-surfaced bearing means to abruptly change the direction of movement of said belt with respect to said predetermined path thereof and permit the strand to continue to move generally along the said path.

3. Apparatus as recited in claim 2 wherein said means to rapidly move said belts includes a relatively large diameter pulley engaged by at least one of said belts and a prime mover to rotate said pulley.

4. Apparatus as recited in claim 2 wherein said means to abruptly change the direction of movement of said belts includes a pair of relatively small diameter smooth-surfaced bearing pins over which the belts move, spaced from said moving means.

5. Apparatus as recited in claim 4 wherein each pin is fixed against rotation.

6. Apparatus as recited in claim 5, further including means to lubricate the belts passing over the surface of the pins.

7. Apparatus as recited in claim 6 wherein said lubricating means includes means to feed cooling fluid between each belt and the engaged surface of its bearing pin.

8. Apparatus as recited in claim 2, further including means to reciprocate at least one belt so as to modify path of movement of the discharged strand.

9. Apparatus as recited in claim 8 wherein said belts move over small diameter smooth-surfaced bearing pins and said means to reciprocate at least one of said belts includes means for oscillating the bearing pin for that belt.

References Cited by the Examiner UNITED STATES PATENTS 2,579,563 12/1951 Gallinger 2261l9 2,685,763 8/1954 Courtney et a1. 226170 2,729,030 l/1956 Slayter 9 2,972,439 2/ 1961 Cunningham et al 65-11 DONALL H. SYLVESTER, Primary Examiner.

S. LEON BASHORE, G. R. MYERS,

Assistant Examiners. 

1. A METHOD OF PRODUCING GLASS FIBERS FROM A SOURCE OF MOLTEN GLASS FLOWING THROUGH A PLURALITY OF ORIFICES WHICH COMPRISES, GATHERING SAID FIBERS INTO A STRAND, INTRODUCING SAID STRAND BETWEEN AT LEAST TWO OPPOSING FLEXIBLE SURFACES, EACH MOVING IN THE SAME DIRECTION AT SUBSTANTIALLY THE SAME HIGH RATE OF SPEED, SAID FLEXIBLE SURFACES BEING ENGAGED WITH ONE ANOTHER DURING THE ,OVEMENT THEREOF FOR A DISTANCE SUFFICIENT TO IMPART A HIGH VELOCITY TO SAID STRAND ENGAGED WITH SAID FLEXIBLE SURFACES, MOVING AT LEAST ONE OF SAID OPPOSING FLEXIBLE SURFACES AWAY FROM THE OTHER OF SAID SURFACES TO PERMIT SAID STRAND TO REMAIN IN CONTACT WITH A MOVING FLEXIBLE SURFACE, ABROUPTY CHANGING THE DIRECTION OF THE MOVEMENT OF THE FLEXIBLE SURFACE HAVING THE STRAND IN CONTACT THEREWITH AT A POINT ON SAID FLEXIBLE SURFACE WHERE UNTIL THE DIRECTION OF MOVEMENT OF SAID LEAST NAMED FLEXIBLE SURFACE IS AT A SHARP ANGLE TO SAID DIRECTION OF MOVEMENT OF SAID STRAND,
 2. IN APPATATUS FOR PRODUCING FIBER GLASS WHICH INCLUDES A SOURCE OF MOLTEN GLASS, A FIBER FORMING BUSHING HAVING A PLURALITY OF ORIFICES THROUGH WHICH MOLTEN GLASS FROM SAID SOURCE FLOWS STREAMS AND WHICH STREAMS ARE ATTENUATED INTO FIBERS, AND MEANS TO GATHER SAID FIBERS INTO A STRAND, THE IMPROVEMENT WHICH COMPRISES, A PAIR OF ENDLESS BELTS HAVING SURFACE PORTIONS WHICH ENGAGE ONE ANOTHER AND BETWEEN WHICH THE STRAND IS FED TO BE ENGAGED BY SAID ENGAGING SURFACE PORTIONS, MEANS TO RAPIDLY MOVE SAID BELTS ALONG A PREDETERMINED PATH SO AS TO MOVE SAID ENGAGED STRAND ALONG THE SAME PATH AND TO APPLY ATTENUATING FORCES TO SAID FIBERS, AND A SMOOTH-SURFACED BEARING MEANS TO ABRUPTLY CHANGE THE DIRECTION OF MOVEMENT OF SAID BELT WITH RESPECT TO SAID PREDETERMINED PATH THEREOF AND PERMIT THE STRAND TO CONTINUE TO MOVE GENERALLY ALONG THE SAID PATH. 